[Elecraft] Mobile from 117 VAC

[Jim Brown]

On 10/9/2017 2:01 PM, Dauer, Edward wrote:
>
> Jim –
>
> Good ideas from you, as always.
>
> The impact of RF on the car’s systems interests me the most, as I 
> hadn’t thought of it before. Yours was a Sequoia.  Mine will be – if I 
> buy it – a Lexus GX which is effectively the Sequoia’s cousin, if not 
> half-brother.  So even if I conquer all the challenges of bonding and 
> antenna-making and all the rest, there is still the risk that HF RF 
> will affect some processor on the vehicle at the worst possible time 
> and place?
>

Yes. BUT -- that was a brand new 2006 model. Let's hope Toyota/Lexus has 
learned something about these issues in 11 years. :)

> How do we deal with that sort of problem? Operate QRP only?
>

I'd say it's a business problem -- that is, between you and 
Toyota/Lexus. It might be worth checking with ARRL about HF mobile in 
current production of these vehicles. MAYBE things have improved. After 
having the issues with my SUV, I did a lot of poking around online and 
found indications that another brand was far better for RFI. But by then 
I'd made a bunch of trips from W9 to W6 and had 45,000 miles on it. :)

> Many years ago (1973) I had a HW-101 in a Fiat Spyder, which in those 
> days still had the traditional coil and condenser ignition system.  To 
> control noise I installed coax  braid over every spark plug wire from 
> the distributor and the line from the coil and whatever else I could 
> at.  Then one day the braid shorted something at one end or the other 
> – right at the point where the Hollywood Freeway goes through Cahuenga 
> Pass and (in those days anyway as I remember it) narrows to three 
> lane, and at about 5:30 PM. With a cold dead Fiat I blocked at least 
> one of those lanes for at least the hour it took me to rip out all the 
> braid while suffering the horns and the hand gestures of about 400,000 
> people whom I made late for dinner.
>
> I don’t want to ever do that again.  How vulnerable are today’s cars’ 
> systems to HF RF?
>

That's a good question to poke around the internet in general and ARRL 
in particular.  Also ask the guys who do serious mobile operation during 
state QSO parties. W0BH, W4NZ, KU8E, and K4ZGB are some guys who have 
done a lot of this.  They also know how to put out a good signal from a 
mobile -- I've worked several mobiles from TN and GA on 80 CW, including 
K4ZGB last month in the TNQP.  And they will have also solved any issues 
with noise from computers or computer power supplies.

73, Jim K9YC